I decided that I wanted to take a pencil, and trace my path through space. The line would follow me around the earth as it rotates on its axis, around the sun over the course of a year, around the galaxy as it rotates around the black hole at its core. And it would never meet its starting point, because by the time I had completed the 250 million year rotation of the galaxy, the whole thing would have shifted, continuing its trajectory through space.

Then I would take a telescope and look back behind me at this looping, arcing, whirling line that never revisits the same point twice, and I would be able to understand my own trajectory through space.

In school we learn that the Earth orbits the Sun, and we often draw its path as a circle. This was the form I imagined my line would take – a series of circular loops and spirals. In reality, our path is elliptical. Well, actually, it’s still not that simple. As the earth travels around the sun its path is influenced by the gravitational pull of the moon as it orbits us, and by the gravitational pull of all the other planets in our solar system as they travel on their paths around the sun.

The more intricate I discovered this path to be, the less confident I became in my mental picture of my path through space.

I came up against a problem of scale. I wanted my line to reflect all the variations and intricacies of real orbits, but the variations are so small compared to the scale of the solar system, that to represent them accurately my drawing would not fit on a piece of paper. Conversely, compared to the scale of me, these variations are substantial. However, to draw them at that scale you would have to lose sight of the bigger picture.

In the end, what you actually see when you look through my telescope, is a moving diagram that traces the path of one of my hanging mobiles from Some Stars Wobble. The circles each indicate the potential path of one weight. Their slow movement within each other (I think they look a bit like organisms in a petri dish) maps the potential configurations of that mobile.

I didn’t want to lose sight of my line, documenting the path of the Earth, so I also included some Earth measurements around the mobile map. The numbers cycle through 0 – 365.2422 for the days of a year, the moon experiences 12 phases, and the tilt of the Earth’s axis completes one full cycle. You can see a video of this work, along with pictures of other works from this exhibition, at clairependrigh.com.

This mobile is part of an exhibition of the same name, currently on show at Sawtooth ARI in Launceston. You can see all the artworks in the show here.

Some stars really do wobble. It’s one of the ways we can tell if a star has a planet orbiting it. Anything that is locked in an orbit with anything else, wobbles.

It’s easier to see If you look at two objects of similar mass that are orbiting each other, for instance, Pluto and its inner most moon Charon. With half the diameter and one-eighth the mass of Pluto, Charon is a very large moon. Its gravitational influence is big enough that both bodies spin around a point in space between them.

All orbital systems have this balance point; it’s called the “barycentre”. When a tiny planet orbits a massive star, the barycentre exists within the body of the star, so instead of making a discernable orbit, the star just appears to wobble.

The barycentre is nicely modelled in a mobile, as each side of each arm needs to be equally weighted. In Some Stars Wobble each mobile starts with two rocks on either end of a wire. I find the balance point, and add a loop and a swivel. Then I add another wire with a rock on the end. This time, the balance point has one rock on one side, and two on the other. To make the mobile hang flat, the balance point needs to be in the centre of mass between the two starting rocks, and the one new rock. The next level balances one rock against three rocks and the pattern continues.

In this mobile, I wanted to see just how complicated a balancing act between rocks in space might be. Imagine how many paths each rock could travel on its journey around this cluster – how many variations are possible.

In astronomy, a wobbling star indicates an orbiting object – the gravity of each object affecting the orbital path of the other.

For this body of work I decided to imagine what it would look like if I could trace my path through space, creating a line the followed me round and round; as the globe spins on its axis, as the Earth orbits the sun, as the solar system revolves, slowly, around the centre of the galaxy. I quickly discovered that this is a more complicated mental exercise than I had anticipated.

I also thought that I might do a couple of posts about individual works in the show, here on my blog – starting with this series of tiny paintings, A Sign in Space.

Claire Pendrigh, “A Sign in Space (NGC 1261)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (NGC 1851)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.1)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Messier 15)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.2)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Messier 19)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.3)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Terzan 5)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.4)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (NGC 2419)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.5)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Messier 80)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Sign No.6)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (Messier 12)”, 2017, oil on board

Claire Pendrigh, “A Sign in Space (47 Tucanae)”, 2017, oil on board

Claire Pendrigh, A Sign in Space (series), 2017, oil on board

This series of paintings takes its title from a story by Italo Calvino, from his volume of “Cosmicomics”. Each story in this collection begins with some kind of scientific hypothesis, followed by a first person narrative recounted by the unpronounceable but irrepressible protagonist, Qfwfq.

In “A Sign in Space”, Qfwfq explains how he once decided to time how long it takes the Earth to complete one revolution of the Milky Way, by creating a sign in space. He leans out over the edge of the galaxy and finds a spot that is undisturbed by the whirling orbit of worlds within, and places his sign. Then he waits.

“So as the planets continued their revolutions, and the solar system went on in its own, I soon left the sign far behind me, separated from it by the endless fields of space. And I couldn’t help thinking about when I would come back and encounter it again, and how I would know it, and how happy it would make me, in that anonymous expanse, after I had spent a hundred thousand light-years without meeting anything familiar, nothing for hundreds of centuries, for thousands of millennia; I’d come back and there it would be in its place, just as I had left it, simple and bare, but with that unmistakable imprint, so to speak, that I had given it.” – Italo Calvino, “The Complete Cosmcomics; A Sign In Space”

In case you are wondering, it takes about 250 million years.

As our protagonist searches the outer reaches of the galaxy for his sign, he starts to worry. What if, after all this time, he can’t remember what his sign looks like? What if he passes it and doesn’t recognise it at all! I imagine his inner voice saying “Is it here? No, over here? I’m sure I passed by here before. It must be just around this corner.”

The need to place himself in the universe, with an identifying mark, becomes an obsession; one that I, and I’m sure many artists, can relate to. It’s the need to create a thing, that exists beyond yourself, that acts as a reference point, that you, and others, can look back on as proof of your existence in that space and that time. I was here.

The clusters of stars in this little series of paintings are based on real “globular clusters”. Globular clusters are spherical collections of stars, tightly bound together by gravity, found in the halos of galaxies (right near the edge). The stars in these clusters are extremely old, perhaps some of the first to have formed in the galaxy.

I like to imagine that these clusters could act as useful landmarks if you were searching the boundary of the galaxy for a sign you had left there. Unfortunately for Qfwfq, it is very hard to measure anything in a universe in which nothing stays still.